(1) Field of the Invention
The present invention relates to a muting device that mutes an internal audio output of electric and electronic equipment, a liquid crystal display television including the muting device, and a muting method.
(2) Description of the Related Art
Televisions that display a broadcasted picture on a display for audiovisual representation have long prevailed in general households as an essential medium to be used to watch entertainment programs, movies, or news. Along with an improvement of the quality of life, televisions equipped with large size screen are gaining popularity. However, CRT-based televisions having been a mainstream in the past have structural drawbacks relevant to a depth, a weight, or power consumption, and have their limitations in increasing the size of a screen.
In recent years, novel display devices different from the cathode-ray tube, such as, a liquid crystal display and a plasma display have been developed due to improvement in an electronic, semiconductor, or material technology. Since the display device is thinner than the conventional cathode-ray tube, it is generically called a flat display panel. The flat display panel designed for televisions has become low-cost and gotten larger in size along with further technological exploitation and profit making of mass-production. Under the favor of an increasing demand derived from a transition to digital television broadcasting and the housing situation in Japan of narrow houses, the flat display panel television is taking over the conventional tube television. The market for the flat display panel is expanding.
Televisions including the flat display panel television naturally provide an audio output when used for audiovisual representation. Depending on the signal level of the audio output, an external sound may be hard to hear.
For example, when a television is used for audiovisual representation, if a telephone call terminates, a trouble may occur. Specifically, a called party may not answer the call because he/she cannot hear a ring. Otherwise, after the called party answers the call, he/she may hardly hear the calling party's voice and may not smoothly proceed with speech. Aside from the trouble with a telephone call, various troubles may occur because of the difficulty in clearly hearing an external sound. Specifically, a person may not hear someone speaking to him/her, smoothly have a talk, or hear a chime generated by an intercom.
Conventionally, the television includes a so-called muting device that can silence an internal sound generated by the television itself or lower the volume responsively to one depression or manipulation in a case where a viewer has to listen to an external sound in order to, for example, make a call. Thus, the internal sound can be readily set to a condition, which causes no trouble in hearing the external sound, by performing a simple manipulation.
However, according to the foregoing method, the viewer himself/herself has to initiate muting at his/her own discretion. When the viewer himself/herself is unaware of a sound, that is, when the viewer cannot hear a ring generated by a telephone and cannot therefore answer a call or cannot hear a chime generated by an intercom, no measures can be taken. Moreover, muting has to be initiated every time it is needed. This annoys the viewer.
As technologies intended to solve the issue of initiating muting in a television, a related art presented below has been disclosed in the past.
In Japanese Unexamined Patent Publication No. 2002-158942, when a telephone call terminates, if a viewer initiates muting in a television, a call termination sound generated by the telephone is automatically registered. Thereafter, whenever a telephone call terminates, muting is automatically initiated.
According to the technology described in Japanese Unexamined Patent Publication No. 2002-158942, the annoyance in initiating muting is resolved. However, after the registration, the call termination sound generated by the telephone is discriminated based on whether a sound registered as a call termination sound to be generated by the telephone is included in sounds collected by a sound collection unit.
The sounds collected by the sound collection unit include an internal sound generated by the television itself. Consequently, for example, if the internal sound includes a component corresponding to the call termination sound generated by the telephone, although the call termination sound is not actually generated by the telephone, termination of a telephone call is recognized. Consequently, muting is automatically initiated.
The foregoing issue is not limited to televisions. The same applies to, for example, stereos, radios, or electric and electronic equipment, which provides an audio output, other then the television.